Can a virtual human increase mindfulness and reduce stress? A randomised trial

Stress is a significant issue amongst university students, yet limited psychological services are available. Mindfulness is effective for stress reduction and can be delivered digitally to expand access to student populations. However, digital interventions often suffer from low engagement and poor adherence. A virtual human may improve engagement and adherence through its humanlike appearance and behaviours. To examine whether a virtual human could reduce stress in university students at least as much as a teletherapist, and more than a chatbot, using a mindfulness intervention. Stressed university students (N = 158) were randomly allocated to the virtual human (N = 54), chatbot (N = 54), or teletherapist (N = 50). 36 participants received each condition. Participants completed one lab session and were asked to do online homework sessions at least twice weekly for four weeks. Changes in self-reported stress and mindfulness, physiological stress indices, homework completion, and perceptions of the agent were compared between groups. Thematic analysis was conducted on participants’ responses to open-ended questions about the interventions. There were significant reductions in stress and increases in mindfulness across all groups. All groups had higher peripheral skin temperature post-intervention, and only the teletherapy group had higher electrodermal activity (reflecting elevated stress) post-intervention compared to baseline. There were no significant changes in heart rate. Homework adherence was significantly higher in the virtual human group, whereas homework satisfaction and engagement were lowest in the chatbot group. Thematic analysis found that people thought the robotic voice of the virtual human could be improved, the chatbot could be improved by adding audio, and that participants experienced feelings of judgement from the teletherapist. Overall, results support use of virtual humans for delivering mindfulness interventions in stressed students. Virtual humans may have the advantage over teletherapy and chatbots of increasing adherence in student populations, but more work is needed to increase perceived empathy and replicate results in other populations.